A tablet of Dilaudid® a strong analgaesic (hydromorphone hydrochloride 1, 2, 3, 4, or 8 mg) derived from morphine and invented in Germany in 1926; it is eight times stronger than morphine via the intravenous route and therefore marginally stronger than heroin.

I finally got relief from the injury after the doctor switched me from Vicodin to some 3 mg Dillies.

(noun) A type of female black cat that is commonly associated with Halloween and is said to provide good luck for its owner. Characteristics include a tendency to over eat, a penchant for napping often, and an adventurous spirit.

My little Dilly is the best. All she does is eat, sleep, and explore, but I'm lucky to have a cat like this.

Dilaudid. A strong pharmaceutical, injectable opioid, usually found in tablet form. At one time these were in demand, but my guess would be that now the big deal is oxycontin.
Also were referred to as "DLs."